Hydraulic check for air drilling units



Sept. 20, 1960 A. 1. ZAGAR HYDRAULIC CHECK FOR AIR DRILLING UNITS 2 Sheets-Sheet 1 Filed Nov. 17, 1958 INVENTOR.

ZAGAR ASHE R ATTORNEY Sept. 20, 1960 A. l. ZAGAR 2,953,122

HYDRAULIC CHECK FOR AIR DRILLING UNITS Filed Nov. 17, 1958 2 Sheets-Sheet 2 INVENTOR.

ASHER 1.2mm?

ATTGRNEY United States Patent HYDRAULIC CHECK FOR AIR DRILLING UNITS Asher I. Zagar, Brooklyn, N.Y., assignor to Ettco Tool & Machine Co., Inc., Brooklyn, N.Y., a corporation of New York Filed Nov. 17, 1958, Ser. No. 774,262

6 Claims. (Cl. 121-45) This invention relates to air drilling units of the type and kind more specifically disclosed in application Serial Number 561,542, filed January 26, 1956, now Patent No. 2,863,339. More particularly, the invention deals with what I term a hydraulic check for controlling speed of operation of the tool in its movement into and through a workpiece consistent with the characteristics of the workpiece employed and the speed of operation of the tool which is required.

Still more particularly, the invention deals with a hydraulic check employing two substantially similar cylinders with a bypass from one cylinder to the other for transmission of the hydraulic medium and with an ad justable needle controlling the pressure discharge of the hydraulic medium in definite control of the operation of the tool.

The novel features of the invention will be best understood from the following description, when taken together with the accompanying drawing, in which certain embodiments of the invention are disclosed and, in which, the separate parts are designated by suitable reference characters in each of the views and, in which:

Fig. 1 is a diagrammatic plan view of an air drilling unit, with parts of the construction removed and broken away and illustrating one of my improved hydro-check mechanisms in elevation.

Fig. 2 is an enlarged sectional View substantially on the line 22 of Fig. 1 through the cylinders of the hydrocheck employed; and

Fig. 3 is an end view of the apparatus, as seen in Fig. 1 of the drawing, and indicating, in dotted lines, the position of the hydro-check in the casing of the unit, with parts of the construction broken away.

Considering Fig. 1 of the drawing, I have indicated at the casing of a drilling unit, substantially as disclosed in the application heretofore identified. Arranged in the casing are two air cylinders 11 and 12, note Fig. 3, the cylinders having intercommunicating passages, as at 13 and 14, controlling operations of pistons in the cylinders in the feed of a tool supporting spindle 15 toward and from a workpiece, the spindle 15 being driven from a drive shaft 16 suitably secured in bearings 17 in one end of the casing 10 through the medium of drive pulleys 18, as noted in Fig. 1 of the drawing.

At 19 is indicated a flexible coupling in the shaft 16 and at 20 is indicated a ball bearing support for the spindle 15 in an adaptor crosshead 21; note Fig. 3 of the drawing. Supported in the ends of the crosshead 21 are piston rods 22 and 23, respectively, which are coupled with the pistons in the cylinders 11 and 12. These rods include ends which protrude beyond inner ends of the cylinders 11 and ,12 and are coupled with a bracket 24, p

which is generally V-shaped in form, as indicated in Fig. 3, being modified to the extent of including an extension 25 centrally thereof, for purposes later stated.

Supported in the casing 10 is a switch 26 actuated by an adjustable pin 27 on the bracket 24. Another switch 28 is adjustable on an adjustment screw 29 and guided on Patented Sept. 20, 1960 rods 30, the housing of the switch also adjustably supporting a stop pin 31 through the medium of a screw 32. The two switches 26 and 28, respectively, control the forward drive of the spindle '15 and the reverse movement thereof. In this connection, it will be understood .that the switch 28 strikes the bracket 24 in operation thereof.

In dot-dash lines I have indicated at 33 in Fig. 1 of the drawing a check valve, which is of standard construction and controls the flow of air to end portions of the respective cylinders 11 and 12 through pipes or communications 13 and 14 and this valve is electrically controlled through actuation of the switches 26 and 28, which are preferably of the micro switch-type.

The structure just described is generally the same as noted in the application heretofore referred to and is illustrated in order to fully understand the operation of my improved hydro-check mechanism which is substituted for and takes the place of the hydraulic cylinder structure, as noted at 47 and its various connected parts illustrated in said prior application.

One disadvantage or objectionable feature of the structure shown in the early application was the fact that controls for the hydraulic cylinder were seated closely adjacent. the crosshead 21 and, at times, adjacent the workpiece operated upon. However, with my improved construction, the hydraulic check is disposed substantially in its entirety within the casing and far remote from the spindle 15 and workpieces, in connection with which the drilling unit is used. Suitably supported within the casing 10 is a hydraulic check mechanism 34, note Fig. 2, which comprises a pair of end plates 35' and 36 secured together by bolts 37, the plates being spaced by a speed control cylinder 38 and bypass cylinder 39, suitably sealed in the plates 35 and 36, as indicated diagrammatically at 40.

Arranged in the cylinder 38 is a piston 41, the rod 42 of which extends out through the plate 36 and is coupled with one offset 43 of a link '44, the other ofiset 45 of which supports a combination adjustable screw and guide rod 46. The rod 46 has a fingerpiece end 47 protruding through one end of the casing 10, as clearly noted in Fig. 1. Adjustment of the screw 46 controls the period of time at which an ofiset dog 48 on a yoke 49 engages the end of the screw 46 in beginning the feed or operation of the piston 41in the cylinder 38. The yoke is pinned or otherwise fixed to the extension 25, as indicated at 49' in Fig. 1 of the drawing. The bracket also includes an ofiset end 50, which is slidably mounted on the rod 46.

From the foregoing, it will be apparent that, in the initial operation of the air cylinders, the tool supporting spindle 15 is quickly moved in the direction of the workpiece to be operated upon and, at the time that the tool reaches the workpiece, the dog 48 will engage the rod 46 and begin actuation of the piston 41 in the cylinder 38. The piston 41 will have suitable seals, as at 41', in the cylinder 38 and, in the drive of the piston 41, the hydraulic medium will be forced through the discharge 51 in the plate 35 into an annular chamber 52 in the plate, the chamber being closed by a sealed plug 53.

Adjustably supported in the plug 53 is a needle valve 54, adjustment of which is provided through the medium of a fingerpiece 54', the valve controlling passage of the hydraulic medium from thechamber 52 through a port 55 into the cylinder 39. This operation will advance a suitable piston 56 in the cylinder against the action of a coil spring 57 for discharge of the hydraulic medium through a substantially V-shaped bypass passage 58 in the plate 35 for admission into the cylinder 38 in back of the piston 41. The passage 58 is controlled by a sealed plug 59.

It willalso appear that exposed to the cylinder 39 and the piston 56 is a passage 60 controlled by a spring actuatedball check 61, the passage 60 opening into the chamber 52 so that, in thereturn' stroke of'the piston 41, or,

in other words, in withdrawal of a tool from .aiworkpiece byractuation of the .air cylinders, the hydraulic medium admitted to the'cylinder39 will be discharged by the a piston 56, assisted in this operation bythe spring 57 to transfer the hydraulic medium back into the cylinder 38 through the passage 51. In the first named actuation of the piston 41, it will 'be understood that the valve 61 will be in seated position, preventing discharge of the, hydraulic medium through the passage 60. a By adjusting the tapered needle valve 54, a very fine degree of control can be provided to govern the speed of operation of the tool in performing a drilling or other operation in a workpiece.

It'will appear that my improved hydro-check mechanism is simple and economical in construction and, by virtue'of its mounting within the casing, will render the entire drilling unit more flexible for use in connection with workpieces of various types and kinds.

with the second named cylin'der, said first named plate including a bypass passage communicating with ends of both of said cylinders, and means, in operative engagement with the rod of said piston, controlling operation of the piston rod'in discharge of a hydraulic medium from the first named cylinder into said second named cylinder. K a

5. A hydraulic control mechanism of the character described, comprising a pair of independent end plates, tubular cylinders supported and sealed, in adjacentrsurfaces of the plates, bolts for securing the plates together in abutment with said cylinders, a piston' in one cylinder including a rod slidable in one of the plates,with an end Having fully described my'invention, what I claim as 7 new and desire to secure by Letters Patent is:

l. A hydraulic check mechanism for air drilling units of the character described, said unit employing a casing with a pair of air cylinders therein, a bracket in said ,casing and supported upon rods of pistons operating'in j said cylinders, said mechanism comprising a pair of hydraulic cylinders mounted in said casing, one of said hydraulic cylinders comprising a speed control cylinder and t the other a bypass cylinder, a piston in said control cylinder having a protruding rod supporting a link, said link having an ofiset, inrwhich a stop and guide rod is adjustably supported, a yoke coupled with said bracket and slidable on "said guide rod, said yoke including a dog operatively engaging the guide rod in movement of said 'piston in the control-cylinder in pressure discharge of a hydraulic medium in'said control cylinder into the bypass cylinder of said mechanism,-an adjustable-needle valve a controlling transmission of the "hydraulic medium into said bypass cylinder, a piston in the bypass cylinder actuated by the hydraulic medium introduced into said bypass cylinder," and means for bypassing the hydraulic medium from said bypass cylinder into the control cylinderr 2. A hydraulic check mechanism as defined in claim 1,

wherein said cylinders comprise tubes mounted and sealed in end plates bolted together and, wherein, said rod and needle valve include fingerpiece ends disposed externally of said housing. a

3. A hydraulic check mechanism as defined in claim 1,

5 wherein said mechanism includes a ball check control passage communicating with the bypass cylinder, and a spring is disposed in the bypass cylinder for actuating the piston in said cylinder in transfer of the hydraulic medium from the bypass cylinder into said control cylin der. 7 a a e 4. A hydraulic control mechanism of the character described, comprising apair of independent end plates, tubular cylinders supported and sealed in adjacent sur faces of the plates, bolts for securing'the plates together in abutment with said cylinders,*a piston in one cylinder ineludinga rod slidable in one of the plates, with an end protruding well beyond said plate, a piston in the other cylinder, a spring normally supporting the second named piston in engagement with the opposed plate'of said mech-v anism, said last named plate having a passage communi-' eating with both of saidcylinders, an adjustable needle valve controlling transmission ofa hydraulic medium from 831d passageinto'the second named cylinder, a

ball check controlling another passage communicating protruding well beyond said plate, a piston in the other cylinder, a spring normally supporting the second named piston in engagement with the opposed plate of said mechanism, said last named plate having a passage communicating with both of said cylinders, an, adjustable needle valve controlling transmission of a hydraulic medium from said passage into the second named cylinder, a ball check controlling another passage communicating with the second named tcylinder, said first named plate including a bypass passage communicating with ends of both of said cylinders, means, in operative engagement with the rod of said piston, controlling operation of the piston rod in discharge of a hydraulic medium-from the first named cylinder into, said second named cylinder, said last named means including an adjustable rod, and an'actuated yoke slidable on'said adjustable rod and including a dog normally spaced from and operatively engaging the endof said" adjustable rod in drive of the piston in said cylinder. a a

6. A hydraulic control mechanism of the character described, comprising a pair ofindependent end plates, tubular cylinders supported and sealed in adjacent surfaces of the plates, bolts for securing the plates together in abutment with said cylinders, atpiston in one cylinder including a rod slidable in one of the plates, with an 'end protruding. well beyond said plate, apiston in the other cylinder, a spring normally supporting the second named piston in engagement with the opposed plate of said mechanism, said last named plate having a passage communicating with both of said cylinders, "an adjustable needle valvecontrollingtransmission of -a hydraulic medium 'from said passage into thersecond named cylinder, a

ball check controlling another passage communicating with the second named cylinder, said first named plate including a. bypass passage communicating with ends of both of said cylinders, means,in operative engagement with the rod of said piston, controlling operation of the piston rod in discharge of a'hydraulic medium from the first named cylinder into said second named cylinder, said last named means including an adjustable rod, an actuated yoke slidable on said adjustable rod and including a dog normally spaced from and operatively engaging the end of said adjustable rod in drive of the piston in said cylinderpand means for coupling said yoke with a driving means. 1

UNITED STATES PATENTS 2,067,492 Kingsbury i Jan. 12, 1937 2,664,859 Green Ian. 5, '1954 2,715,389. W Johnson Aug. 16,1955 2,733,691 Johnson Feb. 7, 1956 2,756,546 Barhorst July 31, 1956 Wallace Sept. 23, 1958 7 FOREIGN PATENTS- r 676,805 Great Britain' Aug. 6, 1952 

